System and method for user-server telecommunication in accordance with performance capabilities of a controller

ABSTRACT

A user terminal exchanges information with a server through a transmission medium. A coupling unit couples the user terminal to the transmission medium in accordance with information from the server. Likewise, the server is controlled in accordance with information from the user terminal. In this manner, communication is created and performed between the server and the user terminal. The user terminal may be a Set-Top Unit which may be adjusted to the transmission medium by, for example, a physical medium converter or the communication itself between the Set-Top Unit and the server may be adjusted as directed by programs installed in the Set-Top Unit which may originate from the server.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 09/394,624,filed Jul. 3, 2000, now U.S. Pat. No. 6,282,715 which is a continuationof application Ser. No. 08/776,566, filed Mar. 21, 1997, now U.S. Pat.No. 6,088,051, which is a 371 of PCT/EP95/03089, filed Aug. 1, 1995.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a system and method fortelecommunication, specifically interactive telecommunication.

2. Description of the Related Art

Communication between the user apparatus and the server is often notpossible as a result of differences in the ways the apparatusescommunicate.

OBJECTS AND SUMMARY OF THE INVENTION

The object of the present invention is to provide means enablinginteractive communication along any chosen transmission medium betweenuser apparatuses of various kinds and a server apparatus.

It is also an object of the present invention to provide meansperforming a minimum number of functions to enable communication betweensaid user apparatus and said server apparatus.

According to the present invention a system is provided, characterizedin that said coupling means comprise means for controlling said userapparatus based on information from said server apparatus and forcontrolling said server apparatus based on information from said userapparatus; and means for creating and for performing communication withsaid server apparatus and said user apparatus.

Furthermore, said system according to the present invention ischaracterized in that said coupling means comprise a Set-Top Unit(Set-Top Unit) and a physical medium converter, in that the means forcontrolling said user apparatus are present in said Set-Top Unit andcomprise mainly a program for a dynamic process down-loaded from saidserver apparatus and stored in a RAM memory and in that means forcreating communicating is a program for a static process stored in a ROMmemory of the Set-Top Unit.

As a result of the above-mentioned characteristic properties of thesystem according to the invention, adjustment is achieved on two levels,namely adjustment of said Set-Top Unit to said transmission medium bysaid physical medium converter and adjustment of the communicationbetween said Set-Top Unit and said server apparatus by programs in saidSet-Top Unit originating from said server apparatus.

According to the present invention, a lign-up of Set-Top Units can bedeveloped as commercial products. Also, in order to promote thedevelopment of interactive digital audio-video services, Set-Top Unitmanufacturers will be left as free as possible to compete in the supplyof these Set-Top Units. Therefore, only a minimal set of functionalitiesis defined in order to be incorporated in a standard. This set can beviewed as a “smart gateway” to interactive digital audio-video services.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be explained in detail with the followingdescription of a preferred embodiment of the invention with reference tothe accompanying drawings, in which:

FIG. 1 is a schematic representation of the configuration of elements inthe system on both sides of a transmission medium;

FIG. 2 is a schematic representation of the Set-Top Unit shown in FIG.1; and

FIG. 3 is a schematic representation of the physical medium convertershown in FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The portion of a telecommunication system according to the presentinvention is shown in FIG. 1.

The coupling means are formed by the Set-Top Unit 1, together with theconnection channel 9 and the physical medium converter 3, the couplingmeans forming a connection between the user apparatus 10 and thetransmission medium 4. The transmission medium 4 is a connection betweenthe coupling means and the server apparatus 2, the server apparatus 2having a similar configuration as the Set-Top Unit 1, which isemphasized with the mirror-line 5 and the representation of the physicalmedium converter 3 by a dashed line.

The Set-Top Unit 1 contains memory space divided mainly into threeparts. The “Operating System” is located in the first part 6 of thememory space, the “Operating System” controlling communication betweenthe physical apparatus of the Set-Top Unit 1 and the programs for staticor dynamic processes running in the Set-Top Unit 1. It should be notedthat an application program interface (API) can run between theOperating System and the programs for static or dynamic processes. Inthe case of interactive communication, for which the telecommunicationsystem according to the present invention is particularly suited, theOperating System is preferably of the Real Time, Multi Tasking, ObjectOriented type and comprises a minimal number of basic instructions. Theoperating system mainly handles memory management and communicationbetween processes by “message handling”. The second part 8 of the memoryspace contains programs for static processes, which ensure correctfunctioning of the Set-Top Unit 1. The third part 7 of the memory spacecontains programs for dynamic processes, which ensure correctcommunication with the server apparatus 2 chosen by the user.

As the server apparatus 2 has a similar configuration as the Set-TopUnit 1, corresponding parts of the memory space of the server apparatus2 are denoted in a similar way by 6′, 8′, 7′, respectively.

At initiation of the communication between the Set-Top Unit 1 and theserver apparatus 2 the dynamic processes are sent to the Set-Top Unit 1by the server apparatus 2. Therefore, initiation of the communicationcan be represented by the following sequence:

-   -   1. Initiation by the user.    -   2. Relevant static processes become active in the Set-Top Unit        1.    -   3. Static processes create a connection with said user apparatus        10 and with said server apparatus 2.    -   4. Static process sends relevant information concerning the        Set-Top Unit 1 in the form of a “Identification Format” to the        server apparatus 2. This identification format declares the        performance capabilities of the Set-Top Unit 1 to the server        apparatus 2 at the beginning of the session. These performance        capabilities relate to memory size available for dynamic        processes, screen driver type or the type of another user        apparatus, remote control type, whether additional programs for        static processes are available (namely the I/O driver and/or a        keyboard driver).    -   5. Static process in the server apparatus 2 assembles programs        for dynamic processes suited to the present Set-Top Unit 1,        where suitability is determined by the information in the        “Identification Format”, the server apparatus 2 assuming certain        parameters for the present Set-Top Unit 1 in the case, when the        “Identification Format” contains insufficient information, where        these assumed parameters are, for example, fixed as a result of        standardization. These parameters comprise preferably a minimum        standardized screen driver or other adjustment unit for a user        apparatus, a minimum standardized memory size for dynamic        processes, a minimum standardized physical user control, being        an elementary remote control, and no additional optional        programs for static processes. These minimum performance        requirements are predetermined, for instance: minimum screen        driver in the form of teletext overlay; minimum memory size for        dynamic processes, for example, 4M bits; minimum physical user        control, preferably a four-“button” cursor plus a        select/unselect “button”, where these “buttons” need not be        physical buttons.    -   6. The server apparatus 2 sends the programs for dynamic        processes required by the Set-Top Unit 1 to the Set-Top Unit 1,        where these programs are stored in the memory space of the        Set-Top Unit 1.    -   7. Dynamic processes in the Set-Top Unit 1 and dynamic processes        in the server apparatus 2 communicate to regulate a stream of        data between the Set-Top Unit 1 and the server apparatus 2.

FIG. 2 is a schematic representation of the configuration of a Set-TopUnit 1.

The programs for static processes are present in the ROM memory 12 andare copied to RAM memory 13 when the need arises for such a staticprocess. Programs for static processes resident in the Set-Top Unit 1mainly comprise programs for controlling functioning of an adjustmentunit for a user apparatus like a screen driver, a keyboard driver or anI/O port driver, reaction to calls, decoding, handling of remotecontrol, handling of “downloaded” programs and a Resident User Interface(RUI).

In the case, where existing display devices only provide an extremelyembedded and elementary mechanism for overlay, a screen drivercontrolling functioning of the display device may be needed. Thisprocess will only remain active as long as a dynamic process does nottake over. Similarly, a keyboard driver can control functioning of aterminal. An I/O port driver can, for example, control functioning of aconnected game console.

A Resident User Interface process is necessary when the Set-Top Unit 1is switched on. This process is then automatically started, for which itis loaded into RAM memory 13, where this process should be minimal. Inthe case of a network application, this process merely enables theSet-Top Unit 1 to connect to one or a very limited number of serverapparatuses 2 or only to the navigation systems supplied by the networkprovider (level 1 in U.S. terminology). Once the Set-Top Unit 1 gainsaccess to the server apparatus 2 or to the network provider navigationsystem, the latter downloads the application software at the beginningof the session, including a user interface. An active Resident UserInterface process is then put on stand-by and only becomes active again,when the session is terminated for whatever reason. This mechanismenables service providers to tailor their user-interfaces to their needs(and also compete for better user-interfaces). The functionality of theRUI is in any case very simply; it merely enables the user to connect toserver apparatuses, which will have their own user-interfaces. It shouldbe noted here, that the Resident User Interface processes could also beused to enable definition of some functions, such as user profile, homeprofile, etc.

The static process for controlling reaction to calls is activated, whenthe user has chosen a server apparatus 2 he wishes to be connected to,or when, for example, a first access to a network and a connection tothe network is required. The call handler is such a process, whichmanagers all network and protocol tasks (for example, SDH/ATM) in orderto establish the connection. If all messages to and from the network areto be handled by this process, it will run as long as the connection tothe network (the session with the server apparatus 2) is active.Alternatively, when the downloaded software communicates with thenetwork directly (and upper-layer protocol-wise with the serverapparatus 2), the call handler is terminated at the moment the call isset-up and the connection has been established. Intermediate scenariosare possible, where the call handler process at all times manages thelower-layer protocols and network signaling, whereas the downloadedapplication software manages the end-to-end protocols. The call handlerprocess depends on the selected network protocols.

In the case of interactive digital telecommunication, for example, MPEG2 coding can be selected for digital A/V coding, preferably as astandard. If the A/V decoding process is performed by a dedicated pieceof hardware, a resident A/V MPEG 2 decoder manager is called for.Microprocessing performance permitting, one could, however, envisage thedownloading of the A/V decoding scheme in software.

A program controlling the remote control process is needed to perform atleast initial remote control operations. It could also include theprocess responsible for initial conditional access (including a smartcard interface driver). Additionally, some resident “accounting”functions could be performed by this process, monitoring the user'sexpenditure. In a similar way as the Resident User Interface downloadedapplication software could take over these functions, in which case thisremote control handler would be deactivated, and would only bereactivated when the session is terminated for whatever reason.

A resident program for “download” handling manages processes in thememory space 7 for dynamic processes. It is activated when the user hasselected a server apparatus 2 to be connected. The application softwareis then downloaded from the server apparatus 2 into the part 7 of thememory space containing programs for dynamic processes, after whichcontrol is handed over to this process. The download process runs aslong as a dynamic process is active. When the last dynamic process iscompleted, control is returned to the Resident User Interface process.

Programs for dynamic processes originating from the server apparatus 2are stored in the RAM memory 13, from where these dynamic processes canrun on the processor 11. Dynamic processes themselves are not residentin the Set-Top Unit 1. All dynamic processes originate from variousserver apparatuses 2 (for example, navigation, service providers orcontent providers). Dynamic processes are loaded in to the Set-Top Unit1 by the download process, which then notifies the operating system oftheir presence. A downloaded process can then start and carry out itsfunctions by, for instance (and if needed) communicating with the staticprocesses through the operating system. Such dynamic processes are, forexample, a tailored user interface, monitor functions, end-to-endprotocols, etc. Dynamic processes can use static processes, whennecessary. The operating system and the download process are preferablyable to accommodate any number of dynamic processes, where the number ofdownloaded processes simultaneously available will only be limited bymemory (RAM 13) capacity.

Preferably, it is possible to have more than one dynamic processdownloaded, for example, if the user pauses one dynamic process to runanother, resuming the first after completion of the second. For example,a user may pause his “video on demand” movie in order to book a flightto where the movie was filmed. The download process is active andensures that only one process has access to the video/audio decoderhardware.

Preferably, the Set-Top Unit 1 contains the following interfaces:network interface (down and return channels); RGB/PAL/SECAM/NTSCinterface; analog/digital audio interface; and a UHF interface. As anoption an interface can be placed between the MPEG 2 demultiplexer andthe video and audio decoders. Also, an I/O (data) interface can beadded. The user control/smart card interfaces for remote control mayalso be provided.

For the network interfaces ATM logical protocols (format andsignaling—including call set-up) independently of the physical mediumare used, either for the down channel or the return channel, which canbe different channels. In this case an ATM adaptation layer (AAL) 5 isneeded for signaling. For the transport of the audio-video data an MPEGtransport stream can be used. Two MPEG 2 transport packets could then becontained in eight AAL 5 cells, optimizing overhead. The MPEG 2 systemlayer for transport streams provides all necessary means for sourceclock recovery through time stamps mechanisms. Alternatively, it ispossible to use an AAL 1 for transporting the MPEG 2 transport stream bycontaining one MPEG 2 transport packet in four AAL 1 cells. An FEC abovethe current AAL 1 is optional, as tests have shown, that flagging anMPEG 2 transport packet loss (or even better, a cell loss through theuse of the cell sequence numbering available in AAL 1) to the MPEG 2decoder enables proprietary error concealment techniques to make anypicture artifact hardly detectable by any viewer.

The programs for dynamic processes should, however, be downloadederror-free at the beginning of the session between the server apparatus2 and the Set-Top Unit 1. In this case, real-time processing is notrequired as no isochronicity is required, unlike in A/V streams. It is,therefore, possible to use an ARQ-type and end-to-end recovery protocol.The express transport protocol (XTP), which is less complex than theTCP/IP recovery protocol, can be used to provide such an error-detectionmechanism.

The RGB/PAL/SECAM/NTSC interface is intended to be connected to astandard scart interface, which is also the case for analog/digitalaudio interfaces.

A UHF interface can be used for old televisions, to which current andmore modem standard audio/video interfaces cannot be connected.

An I/O (data) interface, which can optionally be added, is a transparentinterface (bit stream) allowing connection of other terminals, forexample, a game console, to the Set-Top Unit 1. In this case, theSet-Top Unit 1 is really a “smart gateway” to interactive digitalaudio/video services.

The schematic representation shown in FIG. 3 shows the physical mediumconverter 3.

The connection channel 9 between the Set-Top Unit 1 and the firstconverter 21 is usually not of the same kind as the transmission medium4 between the second converter 22 and the server apparatus 2. Theconverter 3 has a modular configuration in the embodiment shown here, soas to enable simple adjustment to the present transmission medium 4 byusing another converter 22 in the converter 3. It is also possible tomake the converter 3 suitable for several transmission media 4, 4′ byadding a converter 22′ represented by dashed lines, necessitating theuse of a selector 24 provided in the connection between the converters21 and 22, 22′, between the connection channels 25 and 26.

The connection channel 9 is preferably of one type so that at this sideof the converter 3 there is no need for measures like those taken at theother side of the converter 3. To allow for the variety of possibletransmission media 4.

Communication along the connection channel 9 between the physical mediumconverter 3 and the Set-Top Unit 1 can, for instance, be performed withSDH/Sonnet 155 Mbps. However, the output of the physical mediumconverter 3 to the Set-Top Unit 1 is subject to some minimum performancerequirements, namely, in terms of the Bit Error Rate (BER), regardlessof the physical transmission medium 4 used as an access network (coaxialcable, fiber cable, ADSL, etc.). As a result of this mechanism, theSet-Top Unit 1 is completely independent of the type of physicaltransmission media 4 used as access networks.

The physical medium converter 3 can be incorporated in the Set-Top Unit1, even though they have been represented by individual elements in FIG.1 and FIG. 2. Further, the coupling means formed by the Set-Top Unit 1or by the Set-Top and the physical medium converter 3 can beincorporated in the user-apparatus 10 to form a unit therein.

1. A system for communication, comprising: at least one network mediumfor transmitting network data signals; at least one server apparatus fortransmitting the network data signal over the network medium; andcontrol means for controlling said at least one server apparatus;wherein said control means transmits performance capability informationof said control means as data signals over the network medium, andwherein said at least one server apparatus is controlled by said controlmeans based upon information for controlling received by said controlmeans over said network medium, and generated in response to saidtransmitted performance capability information; and wherein the serverapparatus is an audio visual apparatus.
 2. The system according to claim1, wherein the means for creating and performing communication compriseprograms for controlling an adjustment unit for said server apparatus.3. The system according to claim 2, wherein said server apparatusincludes at least one of a screen driver, a keyboard driver, an I/O portdriver, remote control means, means for processing programs to bedownloaded and a resident user interface.
 4. A system for communication,comprising: at least one network medium for transmitting network datasignals; at least one server apparatus for transmitting the network datasignal over the network medium; and control means for controlling saidat least one server apparatus; wherein said control means transmitsperformance capability information of said control means as data signalsover the network medium, and wherein said at least one server apparatusis controlled by said control means based upon information forcontrolling received by said control means over said network medium, andgenerated in response to said transmitted performance capabilityinformation; and a connection channel, connected between the at leastone server and the physical medium converter; wherein the serverapparatus is an audio visual apparatus; and wherein the physical mediumconverter comprises a first converter for converting signals to and fromthe connection channel, a second converter for converting signals to andfrom the network medium and a connection between the first converter andthe second converter.
 5. The system according to claim 1, wherein thecontrol means comprises means to provide the at least one serverapparatus, upon establishment of an initial contact with an additionalapparatus connected to said network medium, an identification format;and wherein the server apparatus comprises selection means to thereafterselect and download a program best suited for the control means.
 6. Aserver apparatus connectable to a network medium for transmission ofinformation via said network medium, comprising: a transmission meansfor transmitting data is said network medium; a control means fortransmitting performance capability information of said control means asdata signals over the network medium, and wherein said server apparatusis controlled by said control means based upon information forcontrolling received by said control means over said network medium, andgenerated in response to said transmitted performance capabilityinformation; wherein the server apparatus is an audio visual apparatus.7. The server according to claim 6, wherein the apparatus for creatingand performing communication comprise programs for controlling anadjustment unit for said server apparatus.
 8. The server according toclaim 7, wherein said server apparatus includes at least one of a screendriver, a keyboard driver, an I/O port driver, remote control means,means for processing programs to be downloaded and a resident userinterface.
 9. The server according to claim 6, wherein the couplercomprises an apparatus for providing the server, upon establishment ofan initial contact with an additional apparatus connected to saidnetwork medium, an identification format; and wherein the servercomprises selection means to thereafter select and download a programbest suited for the coupler.
 10. A system for communication, comprising:at least one network medium for transmitting network data signals; atleast one server apparatus for transmitting the network data signal overthe network medium; and control means for controlling said at least oneserver apparatus; wherein said control means transmits performancecapability information of said control means as data signals over thenetwork medium, and wherein said at least one server apparatus iscontrolled by said control means based upon information for controllingreceived by said control means over said network medium, and generatedin response to said transmitted performance capability information; andwherein said coupler includes a physical medium converter; and aconnection channel, connecting the server apparatus to the physicalmedium converter; and wherein the physical medium converter comprises afirst converter for converting signals to and from the connectionchannel, a second converter for converting signals to and from thenetwork medium and a connection between the first converter and thesecond converter.
 11. A system for communication, comprising: at leastone network medium; at least one server apparatus connectable to thenetwork medium, said server apparatus transmitting information via saidnetwork medium; and coupling means for connecting the server apparatusand the network medium as desired, said coupling means comprising meansfor creating and for performing communication for the transmission ofinformation by said server apparatus, wherein one or more programs aredownloaded from the server apparatus via said network medium, andwherein said one or more downloaded programs controls an additionalapparatus connected to said network medium and allows said additionalapparatus to control a further apparatus connected to said networkmedium based on information from said server apparatus, and regulates astream of data transmitted by the server apparatus as a dynamic process;wherein said coupling means includes a physical medium converter; andsaid system further including a connection channel, connected betweenthe server apparatus and the physical medium converter; and wherein thephysical medium converter comprises a first converter for convertingsignals to and from the connection channel, a second converter forconverting signals to and from the network medium and a connectionbetween the first converter and the second converter.
 12. A serverapparatus connectable to a network medium for transmission ofinformation via said network medium, comprising: a coupler forconnecting said server apparatus and the network medium as desired, saidcoupler comprising an apparatus for creating and for performingcommunication for the transmission of information by said serverapparatus, wherein one or more programs are downloaded from said serverapparatus via said network medium, and wherein said one or moredownloaded programs controls an additional apparatus connected to saidnetwork medium and allows said additional apparatus to control a furtherapparatus connected to said network medium based on information fromsaid server apparatus, and regulates a stream of data transmitted by theserver apparatus as a dynamic process; wherein said coupler includes aphysical medium converter; said server including a connection channel,connecting the server apparatus and the physical medium converter; andwherein the physical medium converter comprises a first converter forconverting signals to and from the connection channel, a secondconverter for converting signals to and from the network medium and aconnection between the first converter and the second converter.
 13. Asystem for communication, comprising: at least one server apparatus fortransmitting data; and a user device connectable to said at least oneserver apparatus for receiving the transmitted data from the at leastone server apparatus, wherein said user device and said at least oneserver apparatus communicate to regulate a stream of data communicatedtherebetween, wherein said user device transmits performance capabilityinformation of said user device to said at least one server apparatusand said at least one server apparatus transmits information in responseto said transmitted performance capability information for controllingsaid at least one server apparatus and/or said user device; and whereinthe at least one server apparatus is an audio visual apparatus.
 14. Asystem for communication, comprising: at least one server apparatus fortransmitting data; and a user device having a resident user interfacetemporarily operable to enable said user device to connect to said atleast one server apparatus to receive information from the at least oneserver apparatus and thereafter entering a standby state, wherein saiduser device transmits performance capability information of said userdevice to said at least one server apparatus and said at least oneserver apparatus transmits information in response to said transmittedperformance capability information for controlling said at least oneserver apparatus and/or said user device; and wherein the at least oneserver apparatus is an audio visual apparatus.
 15. A system forcommunication, comprising: at least one server apparatus fortransmitting data; and a user device temporarily active for receivingthe transmitted data to download information from the at least oneserver apparatus, wherein said download information includes anaudio/visual decoding program, and wherein said user device thereafteris controlled by said downloaded information, wherein said user devicetransmits performance capability information of said user device to saidat least one server apparatus and said at least one server apparatustransmits information in response to said transmitted performancecapability information for controlling said at least one serverapparatus and/or said user device; and wherein the at least one serverapparatus is an audio visual apparatus.
 16. A system for communication,comprising: at least one server apparatus for transmitting data; and auser device for receiving the transmitted data from the at least oneserver apparatus to receive audio/visual transport packets; wherein saiduser device transmits performance capability information of said userdevice to said at least one server apparatus and said at least oneserver apparatus transmits information in response to said transmittedperformance capability information for controlling said at least oneserver apparatus and/or said user device; wherein audio/visual packetloss of said audio/visual transport packets is indicated in the datareceived by said user device; and wherein the at least one serverapparatus is an audio visual apparatus.
 17. A system for communication,comprising: at least one server apparatus for transmitting data; and auser device for receiving the transmitted data including audio/visualtransport packets and controlling information for controlling theoperation of said user device; wherein said user device transmitsperformance capability information of said user device to said at leastone server apparatus and said at least one server apparatus transmitsinformation in response to said transmitted performance capabilityinformation for controlling said at least one server apparatus and/orsaid user device; wherein said user device receives said controllinginformation via a first protocol and said user device receives saidaudio/visual transport packets via a different protocol; and wherein theat least one server apparatus is an audio visual apparatus.
 18. A systemfor communication, comprising: at least one server apparatus fortransmitting information via a network medium; a coupler for operativelyconnecting the server apparatus and the network medium to transmitinformation from said server apparatus over said network medium and todownload information from the server apparatus over said network mediumto a user device, wherein the information downloaded from said serverapparatus and the information in said server apparatus communicate toregulate a stream of data communicated over the network medium betweenthe server apparatus and said user device; said coupler including aphysical medium converter; and a connection channel, connected betweenthe user device and the physical medium converter, wherein the physicalmedium converter comprises a first converter for converting signals toand from the connection channel, a second converter for convertingsignals to and from the network medium and a connection between thefirst converter and the second converter.
 19. Communication methodcomprising the steps of: transmitting information indicating type orperformance capability of a user device over a network medium, receivingat the user device, via the network medium, at least one program fordynamic processing which is generated based on said transmittedinformation indicating type or performance capability of said userdevice, storing said received program at said user device, controllingan audio/video server apparatus based on the received program, andreceiving audio/visual transport packets at said user device via thenetwork medium.
 20. A system comprising: a unit including a processorand a memory system connected to said processor, said memory systemstoring a resident user-interface temporarily operable to connect saidunit to a server via a network medium to receive from said server one ormore programs for dynamic processing of data, said residentuser-interface being overridden by said programs for dynamic processingso as to enter a standby state and to return to an active state whenconnection to said server terminates; and a physical medium converterconnected to said unit via a connection channel, said physical mediumconverter being connected to said server via said network medium, saidphysical medium converter comprising a first converter connected to saidconnection channel, a second converter connected to said network mediumand a connection between said first converter and said second converter.21. A communication method comprising the steps of: receiving at anaudio/video server apparatus, from a network medium, informationindicating type or performance capability of a user device, transmittingto said user device via the network medium at least one program fordynamic processing which is generated based on said transmittedinformation indicating type or performance capability of said userdevice, controlling said audio/video server apparatus based on datareceived from said user device via said network medium, and transmittingaudio/visual transport packets from said audio/video server apparatus tosaid user device via said network medium.
 22. Apparatus connectable to anetwork medium for communicating information via said network medium,comprising: a coupler for operatively connecting a user device, in whichis stored a resident user interface that controls the connection, andthe network medium to provide information for downloading at the userdevice via said network medium, wherein said information includes a userinterface program that puts said resident user interface on standby,said coupler including a physical medium converter; and a connectionchannel for connecting the user device and the physical mediumconverter, wherein the physical medium converter comprises a firstconverter for converting signals to and from the connection channel, asecond converter for converting signals to and from the network mediumand a connection between the first converter and the second converter.